Don Cherry has long ranted on a number of subjects from the insane (Europeans and visors) to the enlightened (no-touch icing and elbow pads). The latter was finally resolved (much to my surprise) with a league-wide common elbow pad. No-touch icing is apparently for fairies so it will never get fixed despite repeated airings. Sadly, blows to the head seem to be going the same way.
The NHL's problem does not lie in elbows to the head as those are generally caught and punished but with the headshots that masquerade as clean hits. Scott Stevens made a career of such hits and the past season has seen an increase (in coverage at least) of those kinds of hits. They do not break any written rules, the players are not leaving their feet, leading with an elbow, or charging across the ice. However, they still leave a bad taste in your mouth.
That Armstrong hit was delivered with the intent to injure and it is not the first time that he has levelled a similar hit. Erin sums it up best (emphasis mine):
You can claim, a la Don Cherry, that Colby Armstrong had nowhere to go, but that still doesn't justify him flying in low, and bringing his shoulder into Patrick Eaves' head (who was having an above-average series before this, by the way). Fair hits aren't always acceptable hits.
Here is a look back at a fair but unacceptable hit from last season's second round. Oh, and for the 'You want to regulate hitting out of the game! You homo!1!!!1' crowd the Ontario Hockey League has implemented a rule governing blows to the head and you would be hard pressed to call those games ballet on ice.